In wireless network such as CDMA, GSM, GPRS, CDMA2000, WDCMA(UMTS), TD-SCDMA and WiMAX etc, when terminal A is calling terminal B and at the same time terminal B is calling terminal A, the network will check A and B's status and inform the respective calling party that the called party is busy, thus the call will not be setup successfully. To a certain extent, this will reduce call success rates and waste network resources.